This invention relates to a novel form of microscopy that allows high resolution mapping of thermal transitions of materials. Measurement of thermal properties of materials is critical to the development of novel materials, including polymers and pharmaceuticals. Understanding the performance of materials at different temperatures is essential for applications like automotive components, construction materials, food packaging, consumer electronics, drug delivery and many others. A key aspect of a material's thermal performance is provided by its thermal transition temperatures, for example rubber/glassy transitions, and melting transitions. Many composite materials are manufactured with micro and nanoscale blends of different materials, for example plastic materials for stiffness and rubbery materials for energy absorption. Conventional techniques for imaging these materials includes TEM and Atomic Force Microscopy (AFM). In AFM, phase imaging, as described in U.S. Pat. No. RE36,488 is commonly used to distinguish different materials in a multicomponent blend. While phase imaging has been very successful for distinguishing some materials from each other, it is primarily sensitive to differences in mechanical properties, for example friction, adhesion, viscolasticity and stiffness. In many cases, it is difficult to attribute the contrast to a quantifiable physical property. And in some cases little or no contrast exists between materials, even when the materials have very different chemical and thermal properties. These materials may, however, have different thermal transition temperatures.
Bulk thermal analysis is a widely used technique. Techniques like differential scanning calorimetery (DSC) are widely used to measure thermal transitions. DSC, however, is performed on bulk samples and the transitions measured are not spatially differentiated. For this reason, extensive research has been performed on local measurements of thermal phase transitions using heated probe tips. Micro Thermal Analysis employed Wollaston wire cantilever probes and measured thermal transitions on the scale of many microns. Nano Thermal Analysis (NanoTA) employs sharp probes typically microfabricated out of silicon based materials to measure transition temperatures over regions on scales of less than 100 nm. Conventional micro and nano thermal analysis measurements, however are measured manually at single points or a handful of points without the ability to spatially resolve detailed variations in thermal transition temperatures. As such, no current technique provides high resolution images of transition temperatures.